B2-Cell Division Flashcards
What is a gene?
A small packet of information that controls a characteristic.
How many chromosomes are there in the nucleus?
46 (23 pairs)
What are the three main stages of the cell cycle?
Stage 1- The cell grows bigger and replicates their DNA so they 2 copies of each chromosome. More sub-cellular structures (mitochondria, ribosomes and chloroplasts) are created ready for the divide.
Stage 2- Mitosis. One set of chromosomes is pulled to each side of the cell and the nucleus divides.
Stage 3- The cytoplasm and cell membranes also divide to form to identical daughter cells.
What is the longest stage in the cell cycle?
Stage 1- Cell growing.
What is differentiation?
The process of unspecialised cells (stem cells) becoming specialised.
When do most cells become specialised in animals?
Very early in life. By the time a human baby is born, most of its cells are specialised
Can specialised cells divide by mitosis?
Yes but they can only produce the same type of cell. Muscle cells divide to produce more muscle cells.
When do most cells differentiate in plants?
Most plant cells are able to differentiate all their lives
Where do undifferentiated plant cells stay?
There are certain growing points or active sites where
